• 제목/요약/키워드: Spread regime

검색결과 23건 처리시간 0.021초

해상풍력 기술의 사회-기술시스템 전환과정에 관한 탐색적 사례연구 (The Case Study on the Niche Experimentation in Offshore Wind Renewable Energy Transition)

  • 김봉균;김덕영;김경남;김동환
    • 기술혁신학회지
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    • 제17권2호
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    • pp.355-379
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    • 2014
  • 새로운 에너지 기술이 기존 사회시스템과 공존하며 확산되는 과정은 저탄소 사회로의 전환을 위해 꼭 필요하지만 어려운 여정이다. 정부주도로 추진되고 있는 서남해 2.5GW 해상풍력사업은 대용량 신재생에너지발전을 중앙전력계통으로 연계하는 것을 목표로 추진되고 있다. 따라서 성공적인 해상풍력 발전의 도입을 위해서는 기존 사회기술시스템의 전환도 병행되어야 한다. 본 연구는 다층적 관점과 전략적 니치관리를 방법론으로 해상풍력기술의 니치전략 적용에 대한 에너지 시스템 전환을 분석한다. 연구결과로서 새로운 기술이 기존 레짐(regime) - 환경상황(landscape)과 연계, 소통을 거쳐 성장하는 과정을 다층적으로 분석하고 에너지체제와 신기술의 관계의 변화를 구조화 하였다. 또한 전략적 니치관리 연구를 적용하여 니치실험 착수단계에서 내재하는 장애요인을 진단하고 해상풍력 실증사업 지연의 원인을 파악하였다. 이를 통해 해상풍력 니치기술이 에너지체제와 다양한 제도 속에서 안정적으로 성장할 수 있다는 실천적 시사점을 도출하였다.

Hydrodynamic fish modeling for potential-expansion evaluations of exotic species (largemouth bass) on waterway tunnel of Andong-Imha Reservoir

  • Choi, Ji-Woong;An, Kwang-Guk
    • Journal of Ecology and Environment
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    • 제40권2호
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    • pp.125-135
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    • 2016
  • Background: The objectives of this study were to establish a swimming capability model for largemouth bass using the FishXing (version 3) program, and to determine the swimming speed and feasibility of fish passage through a waterway tunnel. This modeling aimed to replicate the waterway tunnel connecting the Andong and Imha Reservoirs in South Korea, where there is a concern that largemouth bass may be able to pass through this structure. As largemouth bass are considered an invasive species, this spread could have repercussions for the local environment. Results: Flow regime of water through the waterway tunnel was calculated via the simulation of waterway tunnel operation, and the capability of largemouth bass to pass through the waterway tunnel was then estimated. The swimming speed and distance of the largemouth bass had a positive linear function with total length and negative linear function with the flow rate of the waterway tunnel. The passing rate of small-size largemouth bass (10-30 cm) was 0%at a flow of $10m^3/s$ due to rapid exhaustion from prolonged upstream swimming through the long (1.952 km) waterway tunnel. Conclusions: The results of FishXing showed that the potential passing rate of large size largemouth bass (>40 cm) through the waterway tunnel was greater than 10%; however, the passage of largemouth bass was not possible because of the mesh size ($3.4{\times}6.0cm$) of the pre-screening structures at the entrance of the waterway tunnel. Overall, this study suggests that the spread of largemouth bass population in the Imha Reservoir through the waterway tunnel is most likely impossible.

사강하구의 조석 및 토사이동 (Tide and Sediment Transport in the Keum River Estuary)

  • 최병호;강경구;이석우
    • 한국해안해양공학회지
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    • 제1권1호
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    • pp.31-43
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    • 1989
  • 사강하구의 비선형 조석 및 이에 관련된 퇴적동력학을 조석수치모형을 이용하여 조사하였다. 조석모형은 하구조문대의 노출양상 및 이차원 하구모형과 일차원 감조하천모형을 동적접합시키는 데 역점을 두었다. 모형의 결과는 하구의 강한 봉제소산에도 불구하고 M$_4$분조는 상당한 크기로 산정되었으며 이에 의한 조석비선형은 강한 장조와 상대적으로 약하나 대적시간이 긴 노조로서 제시된 바 하구사주형성의 한 요인이 된다. 또한 모형으로부터 산정된 해저최대봉제응력의 공간적인 분포는 사강하구둑 건설로 인해 군산항접 근수로 및 하구둑 하류부에 큰 퇴적변화가 야기될 수 있음을 제시하고 있다.

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한국영화 검열과 등급분류 제도 변천사에 담긴 비윤리성 탐구 (A Study on Immorality in the Transition of Film Censorship and Rating System in Korea)

  • 정수진
    • 트랜스-
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    • 제2권
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    • pp.39-58
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    • 2017
  • 본 소논문은 자크 데리다의 법과 윤리에 대한 철학들을 바탕으로 정부 검열 시스템에 담긴 한국 영화 정책을 연구하는 데에 목적이 있다. 군사독재 시대 이후 우리나라의 영화 정책은 독재 정권의 프로파간디를 널리 알리고, 사회 통합과 안정을 내세우며 국가적 목표에 부합한 작품을 보호하는 데에 중점을 맞춰왔다. 그리하여 모든 영화 관련 정책은 정부의 엄격한 통제와 감시 안에 존재했다. 그러한 정책은 단순히 영화 선택의 자유만을 제한하는 것이 아니라 창작의 영역까지 침범한다. 자크 데리다는 정의와 폭력과 법에 대한 여러 가지 문제제기를 해왔다. 데리다의 주장들은 윤리적 고찰과 연결되어 있다. 이 소노문은 데리다의 관점에서 한국 정부의 영화 검열 정책에 담긴 폭력성을 짚어보고 윤리적 검열정책의 가능성에 대해 고찰해보고자 한다.

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Recent Progress of Spray-Wall Interaction Research

  • Lee Sang-Yong;Ryu Sung-Uk
    • Journal of Mechanical Science and Technology
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    • 제20권8호
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    • pp.1101-1117
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    • 2006
  • In the present article, recent progress of spray-wall interaction research has been reviewed. Studies on the spray-wall interaction phenomena can be categorized mainly into three groups: experiments on single drop impact and spray (multiple-drop) impingement, and development of comprehensive models. The criteria of wall-impingement regimes (i.e., stick, rebound, spread, splash, boiling induced breakup, breakup, and rebound with breakup) and the post-impingement characteristics (mostly for splash and rebound) are the main subjects of the single-drop impingement studies. Experimental studies on spray-wall impingement phenomena cover examination of the outline shape and internal structure of a spray after the wall impact. Various prediction models for the spray-wall impingement phenomena have been developed based on the experiments on the single drop impact and the spray impingement. In the present article, details on the wall-impingement criteria and post-impingement characteristics of single drops, external and internal structures of the spray after the wall impact, and their prediction models are reviewed.

무선 랜 성능 향상을 위한 링크 계층 트래픽 제어 알고리즘 (Link Layer Traffic Control Algorithm to Improve the Performance of WLANs)

  • 최선웅
    • 한국정보통신학회논문지
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    • 제12권4호
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    • pp.758-765
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    • 2008
  • 오늘날 인프라 무선 랜은 많은 사용자들이 사용하는 중요한 인터넷 접속 기술이다. 무선 랜의 성능은 포화상태에서 시스템의 처리율이 저하되고, 각 노드의 처리율은 시간에 따라 심하게 변화하는 문제점이 있다. 본 논문에서는 링크 계층에서 DCF 시스템의 입력 로드를 조정하여 이러한 문제를 해결하는 트래픽 제어 방법을 제안한다. 트래픽 제어기를 사용하여 DCF로 유입되는 시스템 로드를 적절하게 조정하면 기존 MAC 프로토콜을 수정 없이도 시스템 처리율을 향상시키고 노드의 처리율 변화도 줄일 수 있는 것을 보인다. 또한, 시스템의 상황에 맞는 최적의 시스템 로드를 찾는 동적 제어 알고리즘을 제안하고, ns-2 시뮬레이션을 통하여 성능 향상을 보였다.

东亚古代文化中的阴阳理论之嬗变 (The development of the theory of yin and yang in the ancient East Asian culture)

  • 刘萍
    • 대순사상논총
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    • 제18권
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    • pp.101-122
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    • 2004
  • When people discuss the continental cultural elements in the ancient East Asian culture, people always attach great importance to the two major cultures of Confucianism and Taoism, but offer little explanation to the significant influence of the theory of yin and yang, the important philosophical base of the two major cultures. The theory of yin and yang, existing as the theoretical source at a profounder level, possesses philosophical connotations that are always embedded into the mainstream of thought, religions and customs, displaying its unique glamour in its unique way. Its influence is more than that, however. It has exerted far-reaching influence on and is of significant importance to the development of the ancient culture of East Asia. This article aims at exploring this field of study. After the erudite scholar of The Five Classics made a voyage to the east in the early sixth century, The Book of Changes, the most important Chinese ancient classic expounding the theory of yin and yang, started to circulate among the Japanese court, via Baiji in the Korea Peninsula. As a result, the theory of yin and yang found its way to Japan. Examining the spreading channels, we learn that the theory's dissemination was largely related to the activities of Buddhist monks. Shoutoku Prince, regent of Japan at the time, was himself an enthusiastic supporter of Buddhism and was excelled in the study of The Book of Changes and the theory of yin and yang. In the Twelve Ranks System and Seventeen-article Constitution promulgated by Shoutoku Prince, the influence of the theory of yin and yang and of the theory of the five elements can be visibly discerned. This obviously proves the sublime status of the Chinese theory of yin and yang in Japan, thanks to the victory of the political clique that adored Buddhism. In the shaping course of ancient Japanese culture, the theory of yin and yang served as an important philosophical source of its development. Mythology based on Kojiki and Nihon Shoki, two earliest Japanese books that exist today, record mythological stories about the emergence of the Japanese nation. The notion about the birth of heaven and earth and the forming of Japanese Shinto, expressed in the mythological stories, not only tell us the source and historical progress of the Japanese nation but also the nation's world outlook in the transition from barbarian period to civilized period, as well as the basis for its philosophical thinking. All these were marked with profound influence of the Chinese theory of yin and yang. The theory of yin and yang, as one of the ancient Chinese academic thoughts, was accepted asa political belief when it first spread to Japan. The emergence and establishment of both the Mikado system and the centralized regime in ancient Japan drew largely on the theory of yin and yang and adopted it as an important philosophical basis to deify and aggrandize the "imperial power" so as to protect the authority of the imperial ruling and consolidate the established regime. Following the continuous strengthening and expansion of the centralized state power, the theory of yin and yang was further employed, and gradually "hidden" in Japanese culture with the passage of time, finally becoming the edge tool of ancient Japanese Mikados in exercising political power and controlling the country.

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Surface Micelle Formation of Polystyrene-b-Poly(2-vinyl pyridine) Diblock Copolymer at Air-Water Interface

  • Park, Myunghoon;Bonghoon Chung;Byungok Chun;Taihyun Chang
    • Macromolecular Research
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    • 제12권1호
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    • pp.127-133
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    • 2004
  • We have studied the surface micelle formation of polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) at the air-water interface. A series of four PS-b-P2VPs were synthesized by anionic polymerization, keeping the PS block length constant (28 kg/㏖) and varying the P2VP block length (1, 11, 28, or 59 kg/㏖). The surface pressure-area ($\pi$-A) isotherms were measured and the surface morphology was studied by atomic force microscopy (AFM) after Langmuir-Blodgett film deposition onto silicon wafers. At low surface pressure, the hydrophobic PS blocks aggregate to form pancake-like micelle cores and the hydrophilic P2VP block chains spread on the water surface to form a corona-like monolayer. The surface area occupied by a block copolymer is proportional to the molecular weight of the P2VP block and identical to the surface area occupied by a homo-P2VP. It indicates that the entire surface is covered by the P2VP monolayer and the PS micelle cores lie on the P2VP monolayer. As the surface pressure is increased, the $\pi$-A isotherm shows a transition region where the surface pressure does not change much with the film compression. In this transition region, which displays high compressibility, the P2VP blocks restructure from the monolayer and spread at the air-water interface. After the transition, the Langmuir film becomes much less compressible. In this high-surface-pressure regime, the PS cores cover practically the entire surface area, as observed by AFM and the limiting area of the film. All the diblock copolymers formed circular micelles, except for the block copolymer having a very short P2VP block (1 kg/㏖), which formed large, non-uniform PS aggregates. By mixing with the block copolymer having a longer P2VP block (11 kg/㏖), we observed rod-shaped micelles, which indicates that the morphology of the surfaces micelles can be controlled by adjusting the average composition of block copolymers.

PMS EVOLUTION MODEL GRIDS AND THE INITIAL MASS FUNCTION

  • PARK BYEONG-GON;SUNG HWANKYUNG;KANG YONG HEE
    • 천문학회지
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    • 제35권4호
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    • pp.197-208
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    • 2002
  • Five contemporary pre-main sequence (PMS) evolution model grids are compared with the photo-metric data for a nearly complete sample of low-mass members in NGC 2264. From amongst the grids compared, the models of Baraffe et al. (1998) prove to be the most reliable in mass-age distribution. To overcome the limited mass range of the models of Baraffe et al. we derived a simple transformation relation between the mass of a PMS star from Swenson et al. (1994) and that from Baraffe et al., and applied it to the PMS stars in NGC 2264 and the Orion nebula cluster (ONC). The resulting initial mass function (IMF) of the ONC shows that the previous interpretation of the IMF is not a real feature, but an artifact caused by the evolution models adopted. The IMFs of both clusters are in a good agreement with the IMF of the field stars in the solar neighborhood. This result supports the idea proposed by Lada, Strom, & Myers (1993) that the field stars originate from the stars that are formed in clusters and spread out as a result of dynamical dissociation. Nevertheless, the IMFs of OB associations and young open clusters show diverse behavior. For the low-mass regime, the current observations suffer from difficulties in membership assignment and sample incompleteness. From this, we conclude that a more thorough study of young open clusters is necessary in order to make any definite conclusions on the existence of a universal IMF.

학교시설 제로에너지인증제 시행에 따른 요소별 자립률 분석 (An Analysis of the Self-reliance Rate by Element according to the Implementation of Zero Energy Certification System in School Facilities)

  • 맹준호;김성중;이승민;고현수
    • 교육녹색환경연구
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    • 제20권1호
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    • pp.19-28
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    • 2021
  • 국토교통부는 신(新)기후체제 출범에 따라 건물부분의 에너지절약 및 국가 온실가스 감축목표 달성을 앞당기기 위해 제로에너지건축물 인증제를 시행하고 있다. 2014년 ZEB 조기활성화 방안을 발표 하였으며, 2016년 1월 "녹색건축물 조성 지원법"을 개정하고 제도적 기반을 마련하여 2020년부터 공공부문을 시작으로 2025년 까지 민간부문 까지 단계적 제로에너건축물을 확산시키기 위한 계획을 수립 시행중에 있다. 2020년부터 공공부분에 속하는 학교시설은 제로에너지건축물 의무대상에 포함됨에 따라 본 연구에서는 학교시설 제로에너지건축물 인증시행에 따른 에너지요소별 자립률을 분석하고자 한다.